1) Many teachers are (unjustly) accused of teaching to the test. Most do not do this, but some feel so much pressure for their students to achieve a specific score that they do end up teaching to the test, whether they want to or not. This can make school drudgery for students and steal teachers’ enjoyment of teaching.
2) Some school systems are under great pressure to raise their scores so they have resorted to decreasing (and sometimes doing away with) time spent in recess. This can have negative impact on children’s social, emotional, and academic well-being. (Read more here.)
3) Standardized tests can place a huge amount of stress on students and teachers alike. This can lead to negative health consequences as well as feelings of negativity directed at school and learning in general. (Read more here about how to help students deal with this stress.)
4) As much as test creators try to do away with testing bias, it may be impossible to rid tests of it altogether. I once tutored a 5th grader who did not know what a recipe was. If a standardized test was to ask questions directed at a recipe, that child would have been at a huge disadvantage because most fifth grade students know and have had at least some experience dealing with recipes, but she did not. There is just no way to know for certain that every child being tested has a fair amount of knowledge going into the test.